Lamp socket



Oct. 13, 1942. w, DARLEY 2,298,824

LAMP SOCKET Filed July 22, 1941 lhventor: Wiliiam G. Darley,

His Attorney.

PatentedOct. 13, 1 942 LAIVIP SOCKET William G. Darley, Cleveland Heights, Ohio, as

signor to General Electric Company, a corporation of New York Application July 22, 1941, Serial No. 403,503

(Cl.-1'l3-337) 2 Claims.

In many installations, tubular lamps are mountedend to end to secure a continuous line of light. Since filaments are connected to opposite ends of the lamp, each end of the lamp must be supported in a socket for making an electrical connection to the filament. When the lamps are arranged end to end, lamp sockets must be arranged back to back between the adjacent ends of the adjoining lamps. The areas occupied by the lamp sockets cause dark spots to occur in the line of light and interfere with the production of a uniform line of light. I propose to overcome this objection by providing a lamp socket which may be employed with a series of lamps to give a uniform line of light without dark areas.

It ls in object of 'my invention to provide a new and improved lamp socket which may be used to support a plurality of tubular lamps in line to give a continuous line of light without dark areas.

It is another object of my invention to provide a new and improved supporting device for mount ing a plurality of tubular lamps in a raceway in overlapping relationship.

A further object of my invention is the provision of a lamp socket for supporting a plurality of tubular lamps, such as fluorescent lamps, the socket being arranged to support part of the aux- Each lamp socket comprises a body of insulating material having. a base portion l4 anda plurality of holders [5 and I6 extending upwardly from the base and adapted to receive the spaced contact pins (not shown) at the end of the lamp. The holders I5 and i6 face one another and are offset from each other laterally out of alignment a distance approximately equal to the diameter of the lamp. The holders are also spaced apart longitudinally a distance such that when the lamps are mountedin the socket the ferrule at the end of each lamp is opposite a portion of the light emitting envelope of the.

other lamp. In mounted position, the lamps are offset in overlapping relationship in the manner shown by Fig. 1. This means that no dark areas are present in a line of light devised by placing a number of fluorescent lamps in my sockets in a lighting fixture such as would be the case if a number of conventional sockets were mounted back to back. By mounting the lamp sockets at a slight angle within the associated lighting fixture or raceway; in the manner shown by Fig.

- 1, any number of lamps may be mounted together to secure a substantially straight line of light.

The holders I5 and l6.for receiving the ends of the lamps may be of any conventional type.

illary equipment, such as the starting switch,

Referring to the drawing, I have shown a plu- I rality of tubular discharge lamps l0 and H, mounted in lamp sockets l2 which, in turn, are mounted on the reflecting surface i3 of an electric fixture or raceway. For the purpose of illustration my socket has been shown for use with fluorescent lamps of the type now in commerical use and the description to follow relates to a socket suitable for use with fluorescent lamps. However, my invention may be employed in sockets to receive other types of tubular lamps, for example, tubular lamps having an incandescent filament marketed under the trade name "Lumiline."

By way of example, however, I have illustrated them as of the type disclosed in Reissue Patent 21,545, issued to Anthony J. Marshaus on August 27, 1940, and assigned to the same assignee as the instant application. In this arrangement, the face of the holder is provided with an opening I! which merges with a slot [8 extending to the upper edge of the housing so that the lamp pins may be moved in a straight line into the recess and rotated into engagement with spaced contact members It! and 20. A guiding stud 2| is located in the recess l1 and is provided with a diametrical groove 22 in alignment with the slot I8 for receiving the lamp pins and guiding them into engagement with the contact members. The contact member I9 extends downwardly through the body of the holder to a point within the base M where it is provided with an oiiset terminal portion 23 carrying a terminal screw 24 for connection to the lamp operating circuit. The other contact 20 is likewise terminated with n the base l4 and is provided with a terminal portion carrying a terminal screw 26. The construction of the holder I6 is the same as that of the holder [5 so that a description of holder I6 is believed to be unnecessary. However, the terminals of the corresponding contact members have been denoted 24' and 25', respectively, to identify the manner in which they are connected into the lamp operating circuit in a manner to be described later.

Inasmuch as the holders [5 and it are offset laterally a distance suflicient to provide for overlapping mounting of the lamps andare spaced apart longitudinally a distance suiflcient to overcome the formation of dark areas, it is possible to provide a base portion of suflicient size to accommodate the starting switch which is utilized in the operating circuit of fluorescent lamps. It is not always necessary to provide a mounting means for the starting switch on the base portion of the socket but I prefer to do so because a starting switch is usually provided for each lamp and the base makes a convenient mounting place since the switch is easily accessible by removing the lamps from the socket.

To this end, the base portion M of the socket is provided with a recess 21 to support a starting switch 28. This starting switch may be any one of the well known types now on the market; for example, it may be of the type disclosed in the copending application of Frank C. De Reamer and Adolf C. Mueller, Serial No. 331,566, filed April 25, 1940, and assigned to the same assignee as the instant application. Such a switch is designed to fit in the recess 21 and is provided with spaced contact members 29 which are insertable in keyhole slots 30 formed in the bottom of the recess. Adjacent the keyhole slots are spaced contact members 3| and 32 which are mounted on the base l4 and which cooperate with the contact pins 29 of the starting switch as the latter is mounted in position on the base. member 3| is provided with an extended portion 33 secured in electrical engagement with th contact blade 20 in any suitable manner, as by spot welding. The other contact member 32 is provided with a terminal portion 34 carrying a terminal screw 35 for connection to the lamp operating circuit. In this manner, the starting switch is connected electrically in series with one of the lamp holders, in this case the holder l5. The lamp receiving portions of the holders i5 and it are located a suflicient distance about the base it so that when a starter is mounted on the base, the lamps will extend over the top of the starter, in the manner shown by Fig. 1. This provides a compact arrangement and is one in which the starting switch is readily accessible for replacement.

One manner in which my socket may be incorporated into an operating circuit having a plurality of discharge lamps is illustrated by Fig. 3.

in this illustration, three sockets are shown supporting two fluorescent lamps which form part or a lighting raceway. A starting switch 28 is mounted in each of two of the sockets, one for each lamp, and the sockets ar operatively connected to a ballast 36 in the lines 31 and 38 of an alternating current supply. The installation is controlled by an operating switch 39. The ballast includes a reactor 80 for operating lamp H and another reactor 4| for operating the lamp H]. In the lead to the reactor 4|, a capacitor 42 is inserted, which is shunted by a grid lead 43 and which is adapted to give a power factor correction to the operating circuit of the lamp In in a manner well known in the art. Included in the operating circuit for the lamp i0 is a second reactor 44 which tunes the circuit including the lamp ID, the reactor 4| and the capacitor 42 more nearly to resonance to increase the heating of the lamp filaments in a manner more fully de- Contact scribed in Patent 2,170,457 issued to Harold W. Lord on August 22, 1939, and assigned to the same assignee as the instant application.

Upon closure of switch 39, current flows from pply line 31 through a lead line 45 to the ballast 36; it energizes the lamp H by flowing through the reactor 40, a lead lin 46 to the terminal 24 on the lamp holder l5, then through the right hand filament of lamp H to th other terminal 25, through extension 33 to the starting switch 28, then through a lead line 41 to th terminal 25 of the other lamp holder it, through the left hand filament of the lamp to terminal 23', to lead line 48 and then to the other alternating current supply line 38. Simultaneously, the lamp in is energized by current flowing from the lead line 45 to the capacitor 42, reactor 4|, by a lead'line 49 to the terminal 24 of the lamp holder l5 in the second socket, then through the right hand filament of the lamp ii) to the other terminal 25, by shunt 33 to the other starter 28, by a lead line 50 to the second reactor 44, then by a lead line 5| to terminal 24' of lamp holder 96 in the third socket, through the left hand filament of the lamp H) to terminal 25, to a lead line 52 and then by lead line 48 to the other supply line 38. In this manner, the filaments in the opposite'ends of a corresponding lamp are connected in series so that current flows through the filament to heat them to incandescence. After a predetermined time interval, on the order of one to four seconds, during which time the lamp filaments are being heated, the starting switches 28 open the circuits between the lamp filaments. The inductive kicks created by.the reactors 4B and 4| upon opening of the starting switches cause a discharge to take place in each of the lamps i0 and II, lighting the lamps. Thereafter, the flow of current through the lamps takes place directly through the glow discharge in the body of the lamps so that th starting switches 28 are shortcircuited.

My socket is particularly well adapted for use with fluorescent lamps since that portion of the base between the holder provides a convenient location for the starting switch necessary for operation of such lamps. The starting switch receptacle may be connected directly to one of the lamp holders. However, the socket arrangement may be adapted for use with other types of lamps by making an appropriate change in the contact arrangement of the holder.

What I claim as new and desire to secure by Letters Patent of the United States, is:

l. A socket for mounting a plurality of tubular lamps to secure a line of light comprising, in combination, a housing of insulatin material having a base portion, said housing having holders pro- J'ecting from said base, each of said holders being provided with receptacle means, said holders being arranged in spaced lateral ofiset relationship on said base with the receptacle means facing one another whereby a separate lamp may be mounted on each holder with the ends of the lamps lying in side by side overlapping relationship, and a receptacle including spaced contacts mounted on said base between said holders and adapted to receive an electric device, one of said contacts being electrically connected in series with one of said holders.

2. A socket for mounting a plurality of tubular lamps having spaced contact pins at the ends thereof to secure a line of light comprising, in combination, a housing of insulating material having a base portion, said housing having holdlapping relationship, a receptacle means including spaced contact elements mounted on said base between said holders and adapted to receive an electric device, one of said contact elements being electrically connected in series with one of the contact members on one of said holders.

WILLIAM G. DARLEY. 

